Extension of effective length of tubing



May 27, 1953 T. B. MOCULLOCH EXTENSION OF EFFECTIVE- LENGTH OF TUBING 2 Sheets-Sheet 1 Filed May 17. 1954 ,4. g ,7 V I r m 4 A B C 7 f 4%; 7 M r 7/ 4% Ila INVENTOR. A. ,3,

May 27, 1958 T. B. MCCULLOCH 2,836,247

EXTENSION OF EFFECTIVE LENGTH OF TUBING Filed May 17, 1954 2 Sheets-Sheet 2 IN V EN TOR.

FIG. [3.

wvwmm 5 :The present invention is directed to apparatus for use in a well bore. More'particularly, the invention is dirooted to apparatus 'for use in a cased and tubed well in'avhich the tubing is permanently located in the well. lnlits more specific aspects, the invention is directed to apparatus for use on a tubing string in a cased well. iThei-present invention may be briefly described as a anethodiandapparatus for lengthening the effective length or a tubing string which is permanently arranged in a cased wellf The apparatus comprises a tubular mandrel which is adapted'to be connected to the end-of the tubingx iakrranged and carried by the tubular mandrel on the exterior thereof in sliding relationship therewith is atubular extension member having a diameter slight- 1y greater *than the external diameter'of the mandrel. The extensionime'mber normally held on"the mandrel iby a' lzitehing means (suchas [a shear pin) and 'the' like.

The extension member is provided with-a seal for sealin'g' between'themandreland theextension-member. "The lower end of'themandrel'is provided-with 'astop member t'o' engage with the upper end of the extension member when the'extension'member is in an operative position. .fi'fihe'presentinvention is particularly adapted for use in a c'asedwell .wherein'thetubingis arranged at a point .in thelcasing 'a substantial distance "above a level in the well-at which :certain operations, such as cementing, production, washing, recompleting and the like, are to'be conducted. "Specifically,'the lower open end of the tubing including the mandrel of the present invention is arranged at a'level in the well above the upper of a series -ot;productive strata, sands, zones, intervals, or formationsfrom which oil, gas, or other desirable earth fluids ra mtobe obtained. *When it is'desired to-increase the effective length of thetubing, the extension member which is normally-held on the mandrel by a latch, and the like, is releasedtoallow the extension member to move slidabiy downwardly on the mandrel until it en- ;gages with the stop member on the lower end of the mandrel. This will efiectively lengthen thelength of athe tubingand the mandrel.

. -It is contemplated that the invention may comprise a gzlurality .of extension members concentrically arranged sorta tubular mandrel with .each .extension member being concentric to and .of larger diameter than the extension ,member on which .it is .arranged thereby providing a series of inner and outer extension members. It is contemplated thatthefirst of the extension members will be detachably latched to the tubular mandrel for-support hhereon andsealed'thereagainst while the second .of a

series pf extension members will bedetachably latched iothenext-inner of the extension ,members by alsuitable llatch-forsupport thereon-and likewise. provided a seal. It is also contemplated ,that each of-. the.;i nner;of a plurality of-extensionsm embers will be=provided a member in :ordertov retain the .outer-pf-a seriespf e te s o membe wh t x stn membe s-a ait opetatiye positien.

It will be clear from the foregoing brief description that the present invention allows the lengthening of the eliective length of the tubing permanently set in a well to provide a full open, continuo us passageway to a lower level in the well as desired.

It is contemplated in the present invention that any one or all of a series of extension members may be retrieved and held'against the tubular member or inner of a series of extension members in non-operative position as will be desired.

The present invention will be further illustrated by reference to the drawing in which:

Fig. 1 shows a tubing provided on its lower open end with a tubular mandrel attached thereto carrying an extension member on its outer surfaee in non-operative position;

Fig. 2 is a similar showing to Fig. 1 but illustrates the extension member in an operative position;

Fig. Sis a similar showing to Fig. 1' but illustrates'a plurality of extension members; i Fig. 4 is a sectional view of ==the apparatus withthe tubular extension member ari'anged substantially. coextensive with the tubing; i

Fig. '5 is a detailedfsectional view showing the latching mechanism of Fig. 4; F

Fig. 6 is a partial sectional view of another latching m p; I 4.

. e: 1 a partial ere viewers-n u h r latching 'mechaiiisnt, I Fig 8 sho' s a'l tchrng' d og 'forengaging'the tubular e'-''. ti q Pie 6 n 7 i h e ephing means arranged on thettubular extension member;

Fig. 10 illustrates adevice for moving the extension member downwardly on the tubing;

Fig. '11 shows the device of Fig. 10 in lowering or raising position; i

Fig. 12 is a view of a device being lowered through the tubing for raising the extension member; and

Fig. 13 shows the device of Fig. 12 in operative position. 4

Rcferringnow to the drawing in which identical numerals will be employed to designate identical parts specifically to Fig. l, numeral 1 1 designates ,a casing lining a borehole which has been drilled from the earths surface 12 to penetrate a plurality of formations A, .B, C, and D from which hydrocarbon production maybe had. The casing 11 has arranged therein a tubing 13 to which is attached a tubular mandrel 14. Tubing 13 is attached to mandrel 14 "by means of coupling 13a. The tubular mandrel 14 forms the lower end of the tubing 13 and is provided with a stop member 15. Slidably carried on the tubular mandrel 14 is alight weight tubular extension member 16 whioh suitably may be constructed of a light weight metal such as aluminum or magnesium. 'The extension member 16 is latched to the mandrel 14 by means of a latch 17 and the inner surface of the extension member 16 is provided with a sealing means, such as an O-ring 18, to form a seal with the lower end of the tubular mandrel 14 when the upper end of the extension member comes to rest on the stop 15.

The casing is closed by a well head 19 at the earth's surface 12 and the tubing is closed inat the surface by suitablerneans 20. The tubing :may be provided-with .a how pipe, suchas 21, and the casing witha zpipe 11a as shown.

Referring now to Fig. 2, it will be seen that the-.lateh -17 of Fig. 1 has been released and the extensionmember 16 has moved downwardly on the tubularsmandrel ;-14 until the latch 17 is engaged .with the stop 15 allowing the sealing means 18 to form aseal with the tubular 'quired.

. 3 mandrel 14. It will be seen from Fig. 2 that the eifective length of the tubing 13 has been lengthened such that the tubing extends substantially through formations A, B,andC.

Referring now to Fig. 3, the tubular mandrel 14 is connected to the tubing 13 by coupling means 13a and has arranged thereon an extension member 16, which, similar to Fig. 1, is provided with a latch 17 and a sealing means 18. The extensions member16 has slidably mounted thereon in sliding relationship a second extension member 22 which also may be of light weight metal, such as aluminum or magnesium, and has an internal diameter greater than the external diameter of the extension member 16.

i The extension member 22 is attached to the extension member 16 by a latch, such as 23, and is sealed against the extension member 16 by means of a sealing member, such as an O-ring 24, on the inner surface of the extension member 22.

It is to be noted that in this instance the extension member 16 is provided on the lower end thereof with a stop member 25 which is similar to stop member 15 on the lower end of the mandrel 14.

Referring now to Figs. 4 and 5, the casing 11 has a tubing 13 arranged therein with the lower end of the tubing 13 defining mandrel 14. Arranged on the mandrel 14 and substantially co-extensive therewithis .a tu bular extension member which is designated by the numeral 16. i

The lower end of the mandrel 14 is providedwith a stop member 15 for engagement with an internal shoulder of the extension member 16: when the latter is in an extended position, as shown by the dotted -lines.

The upper end of the tubular extension member 16 defines an annular member 31 w hichis providedwith an annular recess 32 in which'isparr'anged, a pl'ujrality of locking spheres 33 whichare biased outwardly by biasing means, such as helical coil springs 34. As shown in Figs. 1 and 2, the locking spheres 33 engage and lock in a recess 35 of the mandrel 14.:

The upper end of the mandrel 14 is provided with a stop member 36 which. will resist upward travel of the extension member 16. i

The lower end of the tubular extension member 16 has an inwardly projecting annular shoulder 37 for engagement of the lowering tool of Figs. 10 and 11 therewith as Will be described. I i

It will be noted in the embodiments of Figs. 1 to 4 that the effective internal diameter of the extension member 16 is the same as the internal diameter of the tubing 13 and the mandrel 14.

40 and 41, to effect a seal between the mandrel 14 and the tubular extension member 16. The spring 34 is held in the recess 32 by a set screw 42 for adjustment of tension on the spring 34.

It is to be noted in the apparatus of Figs. 4 and 5 that the extension member 16 is provided with vent ports 43 for release of any fluid which may be trapped between the mandrel 14 and the extension member 16..

Referring now to Fig. 6, it will be seen that the PPer end of the tubular extension member 16 has been modified to provide an external shoulder 45 which is engageable with a spring means 46 attached to the mandrel 14 by means of hex-headed screws 47. In this particutherefore, the stop member 36 of Figs. 5 and 6 is not re- Fig. 7 is a modification of the device of Fig. 6 and shows the upper end of the extension member 16 modified to provide internal shoulders 50 and '51 provided with a recess 52. The mandrel 14 has a recess 53 in 4 which is arranged a biasing means 54 attached to the mandrel 14 by hex-headed screws 55.

In the device of Fig. 8 the upper end of the tubular extension member 16 is provided with an annular shoulder 60 defining a recess 61 in which is arranged a pivoted latching dog 62 normally urged outwardly by means of a spring 63. The annular shoulder 60 is provided with recesses 64 and 65 in which are arranged sealing means, such as O-rings 66 and 67, respectively.

The upper end of the mandrel 14 in this embodiment is similar to the upper end of the embodiments of Figs. 4 and 5 and is provided with a recess 32 adapted to reecive the dog 62.

In Fig. 9 the tubular extension member 16 has attached thereto by hex-headed screw 70 a latch spring 71 which is engageable with a latching shoulder 72 on the mandrel 14. In this particular embodiment a stop member 74 is provided below the shoulder 72 to restrict upward travel of the tubular extension member 16.

In Fig. l0 the mandrel 14 which forms part of the tubing 13 has a tool generally designated by the numeral arranged therein on a wire line or cable 81. The tool 80 is provided adjacent its upper end with a packing means, such as a swab cup 82, which forms a seal with the inner surface of the mandrel 14. The tool 80 is provided with recesses 83 on its lower end in which are arranged pivoted dogs 84 which are biased outwardly from the recess '83iby biasing means, such as springs 85. In Fig. 10 the dogs'84 are biased into engagement with the shoulder37. I

In Fig.. 11 the tool 80 is shown pulled up into the mandrel 14;which causes the dogs 84 to be forced inwardly .against and;compres sing the springs 85. I Referring; now to Figs.l2 and 13 atool is lowered through the tubing 13 and the mandrel 14 on a wire line, such as 81,-for retrieving the tubular extension 16. This tool 90 is providedawith a plurality of-dogs 91 which are biased outwardly by biasing means, such as springs not shown. The latching dogs .91 are normally held upwardly in an inoperative position while in the tubing 13, mandrel 14, and extension member 16, as shown in Fig. 12, allowing them to spring outwardly and be held in a horizontal position by shear pins 92 on lowering through the extension member 16 to engage with the lower end 94 of the extension member 16 for raising same back upwardly on the mandrel 14, as will be described.

In operating the device of the present invention and speciii ally with reference to Figs. 4 to 13, the tubing extension member 16 is run into the well on a tubing 13 and specifically with the mandrel 14 in the position as shown in Figs. 1, 3, 4, 5 and 8. Thereafter a tool, such as 80, is run into the well through a lubricator, not shown, and then pumped downwardly, pump pressure being exerted on the swab cups 82 which serve as a piston and cause the tool 80 to be forced downwardly through the tubing 13 and the mandrel 14 until the tool 80 is forced out the lower open end of the mandrel 14. As the dogs 84 emerge from the open end of the mandrel 14, they are biased outwardly by the springs 84 and come to rest against the shoulder 37. By exerting pump pressure on swab cup 82, the tubular extension member is then pumped down until the shoulder 30 engages with the shoulder 15.

Thereafter operations, such as cementing, washing, treating and the like, may be conducted.

When it is desired to retrieve the tubular extension member 16, the tool 90 is lowered on wire line 81 until it issues from the openend of the tubular extension member 16 whereby the dogs 94 spring outwardly and engage with the lower end of the tubing extension 16. Thereafter upward pull on wire line 81 movesthe tubular extension member 16 on the mandrel 84 upwardly until the latching means, such as those illustrated in Figs. 4, S, 6, 7, 8 and 9 become engaged. Continued upward pull onwire line til. causes shear pins 92 to shear and the toolisthen retrieved. The operation.sequence may be repeated as desired where a plurality of tubing extension members, each one telescoping on the other, is provided.

In the practice of the present invention it is contemplated that the etfective length of the well tubing may be varied by mounting the elongated tubular member on the exterior surface of the tubing such that the tubing member and the tubing have a length which is substantially' coextensivel Thereafter the tubular member is moved downwardly on the tubing at least apart of the length of the tubular member whereby' the elfective length of the tubing is extended. Thereafter fluid, such as fluid cementitious material, water, treating agent, such as acid and the-like, may be flowed through the tubing either downwardly therein or upward therethrough when circulation is down the annulus and upwardly through the tubing. After such operations are conducted, the

' tubular member may be moved upwardly on the tubing at least the part of the length of the tubular member previously moved downwardly and latched again into position so that the length of the tube and the tubular member are substantially co-extensive. It is contemplated that the tubing extension-member may be lowered only part of its lengthor. raised only'part of its length after being lowered its full length, as may be desired.-

It-will be seen from the foregoing description taken with the drawing thatthe device of the present invention maybe releasedintooperativepositionby-means of wire line devices-and retrieved into non-operative position. fl'heqdevice of the present inventionis quite usefulin well completionoperations wherein the tubing is located at a level-substantially-above the,.upperrlevel of a series of producing strata -Thepresent .invention allows the effective lengthofthe .tubing,1to be lengthened to conduct operationszatvlowen. leYQlS-jfl the well, as-desired. As an example, indhe-present invention production may be had from a lower of a series ;of producingstrata, such as D, and after production has ceased or become uneconomical-from the strata D, due to water invasion or gas encroachment, and the-like, the extension member 16 may be lowered by unlatching the extension member 16 from the mandrel 14 to allow the effective length of the tubing to be extended to the strata D. Cement may then be pumped down into the area in formation or strata D which is to be sealed where the perforations 9 communicate with the strata D to cause sealing of the perforations.

In conducting the cementing operation, a low strength, r

low water-loss cement, such as disclosed in the patent to R. A. Salathiel, U. S. 2,482,459, may be used although other commercially available low strength, low water-loss cements may be employed. Pressure may be imposed on the cement to cause sealing of the perforations 9 with the formation of a plug therein, if desired. Thereafter the extension member 16 may be raised up on the mandrel 14 by lowering a wire line through the tubing 13 and the mandrel 14 to engage with a suitable engaging means on the-interior thereof. After the extension member 16 has been latched against the latch 17 on the mandrel 14 a small tubing gun of a type well known to the art may be lowered on a wire line through the tubing 13 and fired to form perforations in the casing, well, or

any one of the producing strata'A, B or C, or at any leveltherein .of'the several strata as may be desired. The perforator may be a mechanical perforator or va gun perforator-such-as one employing bullets-or one employing shapedcharges. Thereafter, the extension member may be held on the mandrel 14 -or lowered again to the zone or level from which production is to be had. These operations may be repeated as desired. It is to be understood that other .opera iens' producing and cementing as have been des'cribed maybe conducted with theapparatus -of,the present-inventiog.

Thus it is contemplated that debris,-,s i i r.; l:i as sandapd the like, which has accumulated'in the "well casingpttiib ing may be washed therefrom; by lowering the tubular extension member to the desiredlevel ahd .fld, wirig.a washing liquid, such as oil, fresh or salt water, down the tubing and up the annulus, suchas 31, betweenh andrel 14- and tubing 13 and the casing 11. Of course,,it is appreciated that the washing operation or other operations may be conducted by reverse. circulation with the flow being down the annulus 10 and up through the ex:- tension member 13, mandrel 14 and tubing- 1316. e earthssmface 12. i

The operations which may beconducted in mirates with the present invention may include acidizing, iwelll stimulating, cementing, producing, and. ofthei many operations which are conducted in wellcompletionand recompletion or servicing operations. p The invention, therefore, has wide as has been described and is particularly useful in well completion operations and workover jobs and has the feature, not found elsewhere, that the effective length of the tubing may be lengthened or shortened as desired and still maintain a full open, continuous passageway through which operations, such as gun perforating using a tubing gun, may be conducted, while maintaining thedeviceinQthe well. e The present invention .is, .therefore,; ty because a full opening is maintainedfor the tubin ,when its length is increased or.,decreased. .Inf.g ther wrds, when the tubular memberis in the-extended psition a tubing s a be lowered th e shz hs b nealid the tubular member without requiring then removal ot the tubular member or movement 9 same ppwardly ond ogwn on -m F 2-1 us-imam Thenatureand objects of theprese nyention havipg been completely described claim as new and useful and.to: .secure byletteislatentis:

1. Apparatus .foruse in;well-completi on operatigns and the li e which comprises a tubular mandr el memper adapted to be connected to a tubing shing,,-a.tubular extension member .slidably mounted ".011 land ..ex'tensible below said tubular rfiandrel member, releasable latphing means on one of said tubular members cooperating-with latching means on said other tubular member and,supporting said tubular extension member in retractedppsition on said tubular mandrel member, andon zone of said tubular members cooperating with meanson said other tubular member for maintaining the tubular extension member and tubular mandrel member-incoupled relationship when the tubular extension member -is .in an extended position relative to said tubular mandrel'memher, said tubular extension member being movablesli'dably from retracted to extended position on release of said releasable latching means.

2. Apparatus in accordance with claim 1 in'which'the releasable latching means is on said tubular'extens'ion member. I

3. Apparatus in accordance with claim'l in which the releasable latching means is 'on the tubular man rel member. I if 4. Apparatus in accordance with claim 1 in 'whib'h the cooperating means comprises a stop member on the lower end of the mandrel and an internal shoulderonthe upper end of the tubular member. I

5. Apparatus in accordance 'yvith claiml in which the releasable latching means comprises'atlea'st one latchitfgj dog on' the upper end of the-extensionme able with the latchingmeans on saidlmandre 6. Apparatus in'accordance witli'clai releasable latching means comprises means 1 it said sion member biased into engagement.[with ftl ie.'lmeans on said mandrel. i

7. Apparatus inaecordance e r e;la h as a i a bi n wa ia'iltllih itl the mandrel engaging with latching means on said exten- :sion member at its upper end.

8, Apparatus for use in well completion operations and the like which comprises a tubular mandrel member, coupling means attached to the upper end of said tubular mandrel member and adapted to be connected to a tubing string, a tubular extension member slidably .and sealingly mounted on and extensible below said tubular mandrel member, releasable latching means on one of said tubular members cooperating with latching means on said other tubular member and supporting said tubular extension member in retracted position on said tubular mandrel member, and means on one of said tubular members cooperating with means on said other tubular member for maintaining the tubular extension member and tubular mandrel member in coupled relationship when the tubular extension member is in extended position relative to said tubular mandrel member, said tubular extension member being movable slidably from retracted to extended position on release of said releasable latching means.

9. Apparatus for use in well completion operations and the like which comprises a tubular mandrel member adapted to be connected to a tubing string, a tubular extension member-slidably mounted on and extensible below said tubular mandrel member, sealing means carried by said tubular extension member for sealing between said tubular members, releasable latching means on one of said tubular members cooperating with latching means on said other tubular member and supporting said tubular extension member in retracted position on said tubular mandrel member, and means on one of said tubular members cooperating 'with means on said other tubular member for maintaining the tubular extension member and tubular mandrehmember in coupled relationship when the tubular extension member is in extended position relative to said tubular mandrel member, said tubular extension member being movable slidably from retracted to extended position on release of said releasable latching means.

10. Apparatus for use in well completion operations and the like which comprises a tubular mandrel member, coupling means attached to the upper end of said tubular mandrel member and adapted to be connected to a tubing string, a tubular extension member slidably mounted on and extensible below said tubular mandrel member, sealing means carried by said tubular extension member on its upper end for sealing between said tubular members, releasable latching means on one of said tubular members cooperating with latching means on said other tubular member and supporting said tubular extension member in retracted position on said tubular mandrel member, and means on one of said tubular members cooperating with means on said other tubular member for maintaining the tubular extension member and tubular mandrel member .in coupled relationship when the tubular extension member is in extended position relative to said tubular mandrel member, said tubular extension member being movable slidably from retracted position to extended position on release of said releasable latching means 11. Apparatus for use in well completion operations and the like which comprises a tubular mandrel member adapted to be connected to a tubing string, a plurality of tubular extension members having successively larger diameters slidably mounted on and extensible below said tubular mandrel member, separate releasable latching means on each one ofsaid tubular extension members cooperating with latching means on the next innertubular extension member and supporting each of said tubular extension members in a retracted position on the next inner tubular extension member and on said tubular mandrel member, and means on each one of said tubular members cooperating with means on said next inner tubular member for maintaining the tubular extension memassent? 8 bers and tubular mandrel member in coupled relationship when the tubular extension members are in extended position 'relative to said tubular mandrel member, each of said tubular extension members being movable slidably from retracted to extended position on release of each of said releasable latching means.

12. Apparatus in accordance with claim 11 in which the releasable latching means comprises at least one latching dog on the upper end of the extension member engageable with latching means on said mandrel.

13. Apparatus in accordance with claim 11 in which the releasable latching means comprises means on said extension member biased into engagement with latching means on said mandrel.

l4. Apparatus in accordance with claim 11 in which the releasable latching means is a biasing means mounted on the mandrel engaging with latching means on the extension member at its upper end. e

15. Apparatus for use in well completion operations and the like which comprises a tubular mandrel member, coupling means attached to the upper end of said tubular mandrel member and adapted to be connected to a tubing string, a plurality of tubular extension members having successively larger diameters slidably and sealingly mounted on and extensible below said tubular mandrel member, separate releasable latching means on each of said tubular extension members cooperating with latching means on the next inner tubular extension member and supporting each of said tubular extension members in a retracted position on the next inner tubular extension member and on said tubular mandrel member, and means on each one of said tubular members cooperating with means on said next inner tubular member for maintaining the tubular extension members and tubular mandrel member in coupled relationship when the tubular extension members are in extended position relative to,

said tubular mandrel member, each of said tubular extension members being movable slidably from retracted to extended position on release of each of said releasable latching means. 7

l6. Appar'atus f01' .use in well completion operations and the like which comprises a tubular mandrel member adapted to be connected to a tubing string, a tubular extension member slidably mounted on and extensible below said tubular mandrel member, releasable latching means on one of said tubular members cooperating with latching means on said other tubular member and supporting said tubular extension member in retracted position on said tubular mandrel member, means on one of said tubular members cooperating with means on said other tubular member for maintaining the tubular extension member and tubular mandrel member in coupled relationship when the tubular extension member is in extended position relative to said tubular mandrel member, said tubular extension member being movable slidably from retracted to extended position on release of said detachable latching means, and means on the lower end of said tubular extension member adapted to be engaged by means lowerable through said mandrel member and said tubular extension member for releasing said releasable latching means and moving said tubular extension member from retracted to extended position.

17. A method for varying the efiective length of a well tubing permanently arranged in a well casing with its lower open end above a plurality of hydrocarbon productive intervals in which an elongated tubular member is slidably mounted on a surface of said tubing such that the tubular member is substantially co-extensive with the tubing, and is extensible below the lower end of the tubing which comprises moving said tubular member downwardly on said tubing surface whereby the efiective length of the tubing is extended, flowing fluid material through said tubing and through said tubular member while the tubular member is in said extended position, then moving said tubular member upwardly on said tubing surface to short- 9 r en the efiective length of 'the tubing, and then lowering a perforator through said shortened tubing and operating said perforator at a level belsw the shortened tubing but above the level reached by the extended tubing before it was shortened to form perforations in said casing in one of said hydrocarbon productive intervals.

18. A method in accordance with claim 17 in which the fluid material is cement.

19. A method in accordance with claim 17 in which the fluid material is a washing liquid.

20. A method in accordance with claim 17 in which the fluid material is acid;

21. A method in accordance with claim 17 in which hydrocarbons are produced through the perforations in the casing.

22; A method for conducting operations in a well in which a well tubing is permanently arranged in a well casing with the lower open end of the tubing above a plurality of hydrocarbon productive intervals, in which an elongated tubular member is slidably mounted on. a surface of said tubing, such that the tubular member is substantially co-extensive with the tubing and is extensible below the lower end of the tubing, which comprises moving said tubular member downwardly on said tubing surface whereby the elfective length of the tubing is ex tended, flowing fluid material through said extended tubing, lowering a perforator through said extended tubing, forming perforations in said casing with said perforator in a lower of said hydrocarbon productive intervals, flowing well fluids through said perforations into'said well vand through said extended tubing to the earth's surface then moving said tubular member upwardly on said tubing surface to' shorten the effective length of the tubing, and

-then lowering a perforator through said shortened tubing and operating said perforator at-alevel below the shortened tubing but above the lower of said hydrocarbon 10 productive intervals to form perforations in said casing in an upper of said hydrocarbon productive intervals.

23. A method for conducting operations in a well in which a well tubing is permanentlyarranged in a well casing with the lower open end of the tubing above a plurality of hydrocarbon productive intervals, in which an elongated tubular member is slidably mounted on a surface of said tubing, such that the tubular member is substantially co-extensive with the tubing and is extensible below the lower end of the tubing, which comprises moving said tubular member on said tubing surface whereby the etiective length of the tubing is extended, lowering a perforator through said extended tubing, forming perforations in said casing with said perforator in a lower of said hydrocarbon productive intervals, flowing well fluids through said perforations into said well and through said extended tubing to the earths surface, then moving said tubular member upwardly on' said tubing surface to shorten the effective length of the tubing, and then lowering a perforator through said shortened tubing and operating said perforator at a level below the shortened tubing but above the lower of said hydrocarbon productive intervals to form perforations in said casing in an upper of said hydrocarbon'productive intervals.

References Cited in the of this patent v UNITED STATES PATENTS-.71; 2,087,297

Pew Iuly, 20, 1931 2,101,640 Chonette et a1. Dec. 7, 1937 2,111,062 BIQ n r Mar; 15, 1938 .2,149,4l7 Brown I... Mat. 7, 1939 2,155,609 McClendo et'al. A 1j 25, 1939 2,223,936 Hart 3," 1940 2,543,814 Thompson et Mar. 6, 1951 Baker --...,....--e Dec.* 4, 1951 

1. APPARATUS FOR USE IN WELL COMPLETION OPERATIONS AND THE LIKE WHICH COMPRISES A TUBULAR MANDREL MEMBER ADAPTED TO BE CONNECTED TO A TUBING STRING, A TUBULAR EXTENSION MEMBER SLIDABLY MOUNTED ON AND EXTENSIBLE BELOW SAID TUBULAR MANDREL MEMBER, RELEASABLE LATCHING MEANS ON ONE OF SAID TUBULAR MEMBERS COOPERATING WITH LATCHING MEANS ON SAID OTHER TUBULAR MEMBER AND SUPPROTING SAID TUBULAR EXTENSION MEMBER IS REATRACTED POSITION ON SAID TUBULAR MANDEL MEMBER, AND MEANS ON ONE OF SAID TUBULAR MEMBERS COOPERATING WITH MEANS ON SAID OTHER TUBULAR MEMBER FOR MAINTAINING THE TUBULAR EXTENSION MEMBER AND TUBLAR MANDREL MEMBER IN COUPLED RELATIONSHIP WHEN THE TUBLAR EXTENSION MEMBER IS IN AN EXTENDED POSITION RELATIVE TO SAID TUBULAR MANDREL MEMBER, SAID TUBULAR EXTENSION MEMBER BEING MOVABLE SLIDABLE FROM RETRACTED TO EXTENDED POSITION ON RELEASE OF SAID RELEASABLE LATCHING MEANS. 